Abstract: Dead-time is set to avoid the shoot-through problem of bridge-arm circuits and ensure the reliability of motor drives. Gallium nitride (GaN) based motor drive is sensitive to dead-time setting. Too long dead-time will lead to high reverse conduction loss of GaN device and distortion of motor drive output waveform, and too short dead-time will lead to output capacitance loss and high current spike. In this paper, the effects of the first dead-time and the second dead-time are classified and discussed. The optimization principles of two different dead-time are revealed; based on this, a novel dead-time adaptive control method is proposed. The method can eliminate output capacitance loss and current peak, reduce reverse conduction loss, improve efficiency, effectively reduce total harmonic distortion of load current of motor drive, and improve operation stability of motor without adding additional hardware circuit. Simulation and experiments verify the effectiveness of the novel dead-time adaptive control method, which has obvious advantages over the traditional dead-time design method under heavy load and high switching frequency.